JP4397033B2 - Plasma melting equipment for portable waste treatment - Google Patents

Description

  The present invention relates to a plasma melting processing apparatus for portable waste processing. More specifically, the present invention heats and melts harmful waste such as asbestos waste and incinerated ash containing dioxin at the place where the waste is generated, gasifies the organic component, and melts the metallic component and the nonmetallic component. It is related with the improvement of the apparatus which makes it possible to carry out isolation | separation collection | recovery, and to make a non-metallic component harmless and recyclable by vitrification and rock formation.

  Arc plasma in a plasma melting processing equipment for waste treatment increases the voltage of the plasma or makes the plasma path unstable when the waste is charged. In the worst case, the arc plasma can be extinguished. In the case of a water-cooled metal electrode type plasma torch, the metal part such as the outer cylinder is damaged by a so-called double arc in which current flows from the electrode in the plasma torch to the molten metal via the metal part other than the electrode such as the outer cylinder. Or may interfere with stable driving. Therefore, a device has been devised in which a cover having heat resistance and electrical insulation is provided on the outer periphery of the plasma torch (see, for example, Patent Document 1), but the cover needs to withstand high temperatures during melting, and is durable. There are challenges.

  Further, at the outlet of the plasma melting furnace, the temperature of the molten metal tends to be about 50 to 100 ° C. lower than that in the furnace, and the phenomenon that the viscosity of the molten metal increases and becomes clogged is a problem (for example, Non-Patent Document 1). reference). For this reason, the invention (refer patent document 2) which heats the pipe line part which discharges slag and a metal by high frequency induction heating, and the invention (refer patent document 3) which utilizes the sensible heat of exhaust gas at the tap outlet of slag are made. Yes.

  In a plasma melting furnace using a conventional transfer type plasma torch, a method of generating arc plasma between one plasma torch and a furnace bottom electrode, or between a plurality of plasma torches (see, for example, Patent Documents 4, 5, and 6), A method of generating arc plasma between a plurality of plasma torches and a furnace bottom electrode (see, for example, Patent Document 7) is used. When one plasma torch is used, a gas flow from the plasma toward the periphery and slag outflow are generated, so that the thrown-in waste is pushed to the low temperature peripheral part. In addition, when generating arc plasma between a plurality of plasma torches, their outputs cannot be adjusted independently by current. Furthermore, when arc plasma is generated between a plurality of plasma torches and the furnace bottom electrode, the purpose is to set the intermediate part of the plasma torch at a high temperature, so that the current flowing through all the electrodes is set to be equal. Has been.

  Although slag is electrically conductive when melted, it loses its electrical conductivity when solidified and cannot be energized, making it impossible to generate arc plasma. Therefore, in order to enable easy start-up, for example, a method of stopping the operation by bringing the electrode into contact with the metal layer below the molten slag after the melting treatment (see Patent Document 8), the granular material on the solidified slag A method of generating a plasma arc through the introduction of carbon (see Patent Document 9) and a method of setting and starting a metal on a furnace bottom electrode (see Patent Documents 10 and 11) have been proposed.

As described so far, various ideas have been made and disclosed regarding the plasma melting apparatus, but not only this, but also various techniques for making the plasma melting apparatus movable are disclosed. For example,
(A) A method of inserting a plasma arc torch into a hole in a casing to a predetermined position and dissolving and solidifying the soil around the hole (see Patent Document 12),
(B) A device that melts the soil and treats the generated harmful gas will be added. At this time, the contaminated soil, incinerated ash, etc. will be treated to enable the melting treatment of harmful waste (patent (Ref. 13)
Etc. are disclosed.

  In addition, (c) a technique of thermally decomposing by irradiating a movable infrared laser to pollutants existing in the air, soil, water, etc., and selectively exciting them is disclosed (for example, , See Patent Document 14).

  Furthermore, (d) in the melting technology such as contaminated soil by resistance heating, a steel container is installed in the soil, a ceramic container is installed in it, an electrode is inserted into the container, and Joule heating is performed. There is also a technique of melting waste by the above (for example, see Non-Patent Document 2). The steel container is fitted with a hood so that the generated exhaust gas can be recovered. The collected exhaust gas is detoxified and then released to the atmosphere.

JP-A-10-27687 JP 2002-228137 A Japanese Patent Laid-Open No. 6-300274 JP 9-49616 A JP-A-8-5247 JP-A-8-57441 JP 2001-324125 A JP 2002-213726 A Japanese Patent Laid-Open No. 10-253266 JP 2001-324124 A JP 2002-31486 A JP-A-5-513373 JP 2001-173932 A JP 2001-231881 A Yoshino et al., “Effects of fluctuations in main components of incineration ash on melting characteristics and slag quality”, Journal of Japan Society for Waste Management, 2002, Vol.13, No.6, pp.361-369 Yasufuku, Terada, Kikawada, "Detoxification of Dioxin-Contaminated Soil by Geomelt Method", Journal of Japan Opportunity Association, 2004, vol.107, No.1023, pp. 8-12

However, in plasma melting processing equipment for waste treatment, including equipment that detoxifies and recycles harmful waste contaminated with asbestos waste and dioxin, the arc plasma becomes unstable and stable when waste is introduced. In some cases, it may be difficult to continue operating the processing apparatus, and in the worst case, the plasma torch may be damaged. The reason why the arc plasma becomes unstable is
(1) When a cold substance directly enters the arc plasma, the temperature of the plasma is lowered and the conductivity is lowered (the electric resistance of the plasma is increased). This increases the arc plasma voltage. When the voltage of the arc plasma exceeds the voltage of the power source, the arc plasma may disappear.
(2) In the case of combustible materials, hydrogen and carbon are generated due to rapid thermal decomposition. When these are entrained in the arc plasma, the physical property values (conductivity, etc.) of the arc plasma change abruptly and the voltage of the arc plasma fluctuates.
(3) The shape of the arc plasma may change when a non-conductive concrete lump is introduced. In addition, the arc plasma voltage increases and becomes unstable due to the change of the arc plasma length.
The reason is mentioned. In addition, the reason why the plasma torch is damaged is that when the arc plasma is formed by the path of the electrode, nozzle, and object to be heated in the torch, a large heat load is applied to the portion in contact with the arc plasma and the nozzle. It can be mentioned that a part of the nozzle that has contacted the plasma is melted if the contact time is long (and cooling water leaks out in some cases).

  In addition, as described above, non-metallic waste is conductive when melted, but loses conductivity when solidified. It is desired to start more easily in the case where the start / stop is frequently performed as in the process (for example, the process of driving only in the daytime every day).

  Furthermore, the method of stopping the operation by bringing the electrode into contact with the metal layer below the molten slag after the melting treatment (see Patent Document 8) is to insert the main electrode into the high-temperature molten metal, and the metal part is damaged. Therefore, it cannot be applied to a metal electrode type plasma torch. In the case of a graphite electrode type plasma torch, the solidified molten metal contracts, so that a gap is formed in the furnace, and conduction may be burned out (disappeared). In addition, the graphite may be consumed until the molten slag or metal is solidified.

  In addition, the method of generating a plasma arc by inserting granular carbon into the upper part of the solidified slag (see Patent Document 9) requires that graphite particles be laid in the furnace before ignition, which causes excessive consumption. Goods are needed. Further, since graphite is used as a material for a plasma torch, extra time is required to process it.

  In addition, the method of setting and starting metal on the furnace bottom electrode (see Patent Documents 10 and 11) is not suitable for a processing apparatus that frequently starts and stops because work for removing slag is required at each start-up. Therefore, it is considered to be applied to ignition after large-scale construction that is a large-scale furnace premised on continuous operation and is replaced with a new state or a refractory inside the furnace. If it does so, the width | variety of the processing apparatus which can apply this method will be limited.

  The above is the problem relating to the plasma melting apparatus itself, but there is also the following problem with respect to the prior art that makes the plasma melting apparatus movable.

  That is, first, the technologies listed as (a) and (b) are methods that directly melt the soil by non-transfer arc plasma and have no furnace. Although effective, there is a problem in that soil excavation is necessary because it does not have a furnace. In general, excavating soil for waste disposal is not economical because waste is discharged from a certain processing device or generated in daily life and business activities.

  In the case of technology (c), it is characterized by selective thermal decomposition of only harmful chemical substances, but it cannot be applied when harmful chemical substances and other safe substances cannot be separated. There's a problem.

  In the case of the technique (d), since the melting furnace is assembled in the soil at the waste disposal site, there is a problem in that it lacks mobility, for example, it takes many days to assemble and remove on-site. Furthermore, since all the melting processes are batch processes, there is a concern that work efficiency and energy efficiency may be deteriorated because the melting operation is frequently started and stopped to extract the molten solidified product. In addition, hazardous waste contaminated with asbestos and dioxins may not be able to move due to residents' movement, etc., because there is concern about the spread of waste due to accidents during transportation. Although it is necessary to melt these wastes at a high temperature as a treatment method, a treatment apparatus that can be easily assembled at a place where the waste is generated and can be quickly moved to another place has not been developed.

  Therefore, the present invention is a plasma processing apparatus for waste treatment that enables stable operation without impairing the stability of the arc plasma and that can be easily started at the start of the apparatus, and is movable. Therefore, an object of the present invention is to provide a portable waste processing plasma melting treatment apparatus that enables detoxification processing at a place where harmful waste is generated.

  In order to achieve such an object, the invention described in claim 1 is characterized in that a graphite electrode type plasma torch capable of continuing the melting process even when contacting with the waste as the object to be melted is disposed in the vicinity of the waste inlet. On the other hand, a metal electrode type plasma torch that generates arc plasma with high directivity is disposed in the vicinity of the discharge port of the waste after melting treatment, and a furnace facing these graphite electrode type plasma torch and metal electrode type plasma torch A plasma melting treatment apparatus for waste treatment provided with a bottom electrode, which is characterized in that it can be loaded on a moving medium such as a vehicle, a ship, a freight car, an airplane.

  Since the arc plasma tends to become unstable at the time of waste input, the plasma processing apparatus for waste processing according to the present invention continues the melting process even if it comes in contact with waste or molten metal near the waste input port. A graphite electrode type plasma torch that can be used is arranged so that it is not necessary to pay attention to the contact between the plasma torch and the waste. In addition, when a graphite electrode type plasma torch is used in this way, it is possible to operate with a short gap (gap length) between the graphite electrode type plasma torch and the molten metal. It is possible to suppress fluctuations in the length of the plasma and avoid arc plasma instability.

  On the other hand, a metal electrode type plasma torch having high directivity of arc plasma is arranged in the vicinity of the outlet, so that the molten metal in the vicinity of the outlet can be heated accurately. In the vicinity of the hot water outlet where the melting is completed, the liquid surface has relatively little unevenness, and there is no problem of contact with waste or the like as in the waste inlet. Therefore, this metal outlet uses a metal electrode type plasma torch with excellent arc plasma directivity and heating efficiency to accurately and efficiently heat the molten metal in the vicinity of the hot metal outlet and raise the temperature of the molten metal to prevent solidification. The gate is not blocked. As a result, according to the plasma melting treatment apparatus for waste treatment, it is possible to avoid the instability of the arc plasma, facilitate the hot water discharge, and perform a stable operation. In addition, according to the present invention, there is no problem such as damage of metal parts, progress of graphite consumption, preparation of extra consumables, and there is no need to remove slag at every start-up, so frequent start / stop It is also suitable for a processing apparatus that performs the above.

  In addition, the plasma melting apparatus for waste treatment is a portable apparatus that can be loaded on a moving medium such as a vehicle or a ship. Therefore, it is possible not only to install the processing apparatus in any place, but also to move the apparatus itself on a moving medium. Therefore, not only the generated waste is transported to the place where this processing equipment is installed and melted, but also the equipment itself is transported to the place where the waste is generated and melted and detoxified at that place. Is also possible.

In such a portable waste processing plasma melting treatment apparatus, it is preferable that the graphite electrode type plasma torch and the metal electrode type plasma torch are controlled to be heated independently. In such a case, it becomes possible to precisely control the heating energy in accordance with various situations such as the introduction of waste, the extraction of molten metal, the progress of melting, etc., and the operation with high energy efficiency can be performed. In addition to this, it is possible to further improve energy efficiency by independently controlling the cooling water supply and the gas supply. The portable waste processing plasma melting treatment apparatus according to claim 1 of the present application includes a first power source for supplying power to the graphite electrode type plasma torch and a second power source for supplying power to the metal electrode type plasma torch. The graphite electrode type plasma torch and the metal electrode type plasma torch are controlled to be heated independently.

Moreover, the plasma melting treatment apparatus for portable waste treatment includes a short circuit that connects the graphite electrode type plasma torch and the furnace bottom electrode, and a switch that opens and closes the short circuit, as in the first aspect of the invention. At the start of the plasma melting apparatus, a graphite electrode type plasma torch is connected to the furnace bottom electrode to generate arc plasma between the graphite electrode type plasma torch and the metal electrode type plasma torch. Ru der while separating the formula plasma torch from the furnace bottom electrode. At the time of start-up, by making the graphite plasma torch the same potential as the furnace bottom electrode, it becomes possible to generate arc plasma between another plasma torch (metal electrode type plasma torch) and the graphite electrode type plasma torch. After the molten metal is formed, it is possible to operate as a plasma torch in which the power supply can be independently controlled by separating the graphite electrode type plasma torch from the furnace bottom electrode.

Further, in such a portable waste processing plasma melting apparatus, at least one of the graphite electrode type plasma torch and the metal electrode type plasma torch approaches the other plasma torch as in the second aspect of the invention. It is preferable that separation is possible. In such a case, the arc plasma can be more easily generated by adjusting the interval between the graphite electrode type plasma torch and the metal electrode type plasma torch at the time of starting the plasma melting treatment apparatus.

Further, as in the invention of claim 3 , comprising a conductive refractory having the same potential as the furnace bottom electrode installed at a height that is higher than the liquid level of the waste molten metal and at least does not adhere to the slag, It is also preferable to generate arc plasma between any one of the plurality of plasma torches and the conductive refractory when starting the plasma melting apparatus. When the temperature in the plasma melting furnace decreases after the melting process is completed, the solidified slag covers the furnace bottom electrode, making it impossible to flow electricity. If a refractory with a certain temperature is installed, arc plasma is generated between any one of a plurality of plasma torches and the conductive refractory when starting up the plasma melting treatment apparatus for waste treatment. It becomes possible to start up simply.

More portable waste disposal for plasma melting treatment apparatus, as claimed in claim 4, it is preferable that the furnace body portion including at least a plasma melting furnace has a tiltable structure. The plasma melting apparatus having such a structure can forcibly discharge molten metal by tilting the plasma melting furnace.

Furthermore, it is preferable that the plasma melting processing apparatus for processing portable waste is made smaller than the size of the container as described in claim 5 . In such a case, the container can be loaded with sufficient margin on a freight car or a ship that can be loaded with containers.

  As is apparent from the above description, the plasma melting treatment apparatus for waste treatment according to claim 1 is a combination that makes use of both the high stability of the graphite electrode type plasma torch and the high heating ability of the metal electrode type plasma torch. In addition, it is possible to avoid instability of the arc plasma and to accurately heat the molten metal in the vicinity of the outlet and prevent the outlet from being blocked. For this reason, it is possible to perform a stable operation without impairing the stability of the arc plasma.

  In addition, since the apparatus itself is portable, efficient detoxification processing can be performed at the place where harmful waste is generated. That is, in the past, it was inevitable to move various harmful substances to the processing base. However, according to the present invention, the apparatus itself has mobility, which is associated with the movement of waste (waste transportation). Risk can be completely avoided. Furthermore, if you move to various locations and perform waste treatment, it will be operated as a plasma melting treatment device by that amount, so it is inevitably expected that the operating rate will be greatly improved, and thus it is economically superior. It will be. In addition, since the processing equipment itself is located locally, it is advantageous in that it is not necessary to provide a final disposal facility far away even if harmful substances are scattered in various regions.

  Furthermore, since the plasma melting processing apparatus for portable waste processing according to the present invention uses electric power with the most infrastructure as an energy source, it is advantageous in that it can be applied in various places and in a wide area. is there. Moreover, the use of clean energy such as electric power in this way also minimizes secondary environmental pollution.

Further, a power supply corresponding to each plasma torch, the portable waste disposal for plasma melting treatment device according to claim 1, wherein as heating controls graphite electrode type plasma torch and the metal electrode type plasma torch independently According to this, since it becomes possible to precisely control the heating energy in accordance with various situations such as the introduction of waste, the extraction of molten metal, the progress of melting, etc., an operation with high energy efficiency can be performed. In addition, the energy efficiency can be further improved by controlling the cooling water supply and the gas supply independently.

In addition, according to the plasma melting apparatus for portable waste treatment according to claim 1 , when the apparatus is started, the graphite electrode type plasma torch is connected to the furnace bottom electrode, and the graphite electrode type plasma torch and the metal electrode type plasma torch are We have established a start-up method based on the assumption that the solidified slag has no electrical conductivity, such as generating an arc plasma between them and disconnecting the graphite electrode type plasma torch from the furnace bottom electrode after the start-up is completed. It is possible to start up.

Further, according to the portable waste processing plasma melting processing apparatus according to claim 2 , arc plasma is more generated by adjusting the interval between the graphite electrode type plasma torch and the metal electrode type plasma torch at the time of startup of the apparatus. You can create an easy situation.

Furthermore, according to the plasma melting processing apparatus for processing portable waste according to claim 3 , since the arc plasma is generated between the plasma torch and the conductive refractory when the apparatus is started up, it can be started up easily. Can do.

In addition, according to the plasma melting processing apparatus for portable waste processing according to claim 4 , since the molten metal can be forcibly discharged by tilting the plasma melting furnace, it becomes possible to quickly process the waste, It is advantageous when moving to the place of occurrence and processing.

Further, according to the plasma melting processing apparatus for portable waste processing according to claim 5, since it can be mounted on a freight car or a ship that can be loaded with containers with sufficient margin, it is possible to move by freight car or ship as well as a car. Is even easier.

  Hereinafter, the configuration of the present invention will be described in detail based on an example of an embodiment shown in the drawings.

  1 to 6 show an embodiment of the present invention. The plasma melting treatment apparatus 1 for waste treatment according to the present embodiment is provided with two plasma torches per unit (one machine). Specifically, the waste in which arc plasma is likely to become unstable. The graphite electrode type plasma torch 2 is arranged on the inlet 4 side, and the metal electrode type plasma torch 3 is arranged on the side of the outlet 5 where the flat molten metal 14 without unevenness is formed (see FIG. 1). ). Although the graphite electrode type plasma torch 2 is inferior in heat transfer efficiency to the molten metal 14 as compared with the metal electrode type plasma torch 3, the electrode is consumable, so that the melting treatment can be continued even if it contacts with waste or the molten metal 14. There are advantages. On the other hand, the metal electrode type plasma torch 3 has to avoid operation such as contact with waste or molten metal 14 in order to prevent damage to metal parts such as nozzles, but due to the thermal pinch effect by the gas flow and nozzles. Arc plasma with high directivity can be generated, and high heating efficiency can be achieved.

  The “waste” in the description of the embodiment of the present invention is before melting, and is composed of one or more of metal, incombustible material, and incombustible material (combustible material and incombustible material). . When this is treated at a high temperature, the combustible material becomes soot or gas, and the metal and the incombustible material are melted. If one or more of the metal and the non-combustible material is melted, it becomes “molten metal”. When the incombustible material melts and hardens, it becomes “slag”, and when this slag melts, it becomes “molten slag”. Further, at the time of melting, a two-layer structure is formed in which the molten metal is formed in the lower part and the molten slag is formed in the upper part due to the difference in specific gravity.

  In the following, the main body of the processing apparatus 1 will be described in the portable waste processing plasma melting processing apparatus according to the present invention (see FIGS. 1 to 6), and then the configuration for making it portable will be described. (See FIGS. 7 to 12).

  The graphite electrode type plasma torch 2 and the metal electrode type plasma torch 3 in the present embodiment are both elongated rods as shown in FIG. 1 and penetrate the furnace wall of the plasma melting furnace 13 (more specifically, It is installed so as to penetrate the ceiling wall up and down. Each plasma torch 2, 3 has a mechanism that can be driven freely in the vertical direction (axial direction) and the turning direction, and is inserted into the plasma melting furnace 13 (the part protruding into the plasma melting furnace 13). Can turn and move up and down. An example of the drive mechanism for turning is a mechanism that is composed of two stages 19 and 20 that can be driven independently in the X direction and the Y direction, and is attached to the upper part of the plasma torches 2 and 3 (see FIG. 5). In the case of such a mechanism, it can be driven independently in the X direction and the Y direction so that it can perform a circular motion (turning motion). Movement is also possible. Further, at least one of the graphite electrode type plasma torch 2 and the metal electrode type plasma torch 3 is in the front-rear direction (in this case, the front-rear direction is a direction connecting the waste inlet 4 and the hot water outlet 5; In other words, it has a mechanism for moving in the right and left direction), and can approach or move away from the other plasma torch. The longitudinal movement in this case can be dealt with by making the turning range wider than the range of forward and backward movement when the above-described turning mechanism is provided.

  In the present embodiment, the supply of cooling water and gas to the graphite electrode type plasma torch 2 and the metal electrode type plasma torch 3 and the control thereof are performed as follows (see FIG. 6). That is, the gas is supplied from the supply device 15 through the pressure reducing valve 16, the header 17, and the flow meter 18 using a supply system following the graphite electrode type plasma torch 2 and the metal electrode type plasma torch 3. The header 17 is for branching gas, and for example, a pipe such as a pipe closed at both ends can be used. A specific example of the supply device 15 here is a cylinder, but a compressor is used when air is used instead of gas, and a nitrogen production apparatus is used instead of a cylinder when nitrogen is used. If the graphite electrode type plasma torch 2 and the metal electrode type plasma torch 3 use different gases, two supply systems of “supply device 15 → pressure reducing valve 16 → flow meter 18 → plasma torch” should be prepared. become. Further, although not shown, the cooling water is also branched from the cooling water supply device through the header, and supplied to each plasma torch through a flow meter, in the same manner as the gas supply / control described above. The amount of gas or cooling water supplied by such a supply system can be independently controlled regardless of whether or not a molten metal is formed in the plasma melting furnace 13. Since the graphite electrode type plasma torch 2 can be operated without a plasma gas, the gas supply system for the graphite electrode type plasma torch 2 can be omitted.

  An electrode (this electrode is referred to as “furnace bottom electrode” in this specification) 6 is provided on the bottom of the plasma melting furnace 13 (see FIG. 1). The furnace bottom electrode 6 is disposed so as to face at least one of the graphite electrode type plasma torch 2 and the metal electrode type plasma torch 3. For example, the furnace bottom electrode 6 in this embodiment is disposed near the metal electrode type plasma torch 3 and faces the metal electrode type plasma torch 3 (see FIG. 1).

  A power source for generating arc plasma is connected to the graphite electrode type plasma torch 2, the metal electrode type plasma torch 3, and the furnace bottom electrode 6 (see FIG. 1). In the case of the present embodiment, the first power source 7 and the switch 12 are provided in the middle of the circuit connecting the graphite electrode type plasma torch 2 and the furnace bottom electrode 6, and further the metal electrode type plasma torch 3 and the furnace bottom electrode 6. A second power supply 8 is provided in the middle of the circuit connecting the two (see FIG. 1). In addition, the power sources 7 and 8 are separate as shown here. For example, when there is a portion that can be used in common in the contents of the power supply unit, the power sources 7 and 8 are configured by a single power supply unit and each is controlled. It is also possible. Moreover, the short circuit 9 in parallel with the 1st power supply 7 and the switch 12 is provided, and the switch 11 is provided in the middle of this short circuit 9 (refer FIG. 1). According to the waste processing plasma melting apparatus 1 of this embodiment provided with such a circuit, the power supplied to the plasma torch can be independently controlled as follows.

  That is, at the time of heating and melting, the circuit switch 12 is closed and the switch 11 is opened. In such a case, there are a plurality of power systems such that the first power source 7 supplies power to the graphite electrode type plasma torch 2 and the second power source 8 supplies power to the metal electrode type plasma torch 3. The arc plasmas 2 and 3 can be independently controlled by the first power source 7 and the second power source 8. Therefore, it is possible to control the heating by controlling the arc plasma in each plasma torch 2, 3 according to the melting treatment status such as the amount of waste input from the waste inlet 4, the amount of molten metal 14 discharged, the progress of melting, etc. .

  Further, when starting up the plasma melting treatment apparatus 1 for waste treatment, the second power source 8 → the metal electrode type plasma torch 3 → the graphite electrode type plasma torch 2 is opened by opening the switch 12 and closing the switch 11. It is possible to form a single current path that circulates as follows: switch 11 → furnace bottom electrode 6 → second power source 8 (see FIG. 2), whereby the graphite electrode type plasma torch 2 and the metal Arc plasma can be generated between the electrode type plasma torch 3 (note that current paths are indicated by arrows in FIGS. 2 to 4). At this time, one or both of the plasma torches are moved back and forth by the mechanism capable of moving back and forth as described above to narrow the distance between the plasma torches 2 and 3 to a distance necessary for ignition of the arc plasma, so Arc plasma can be generated to melt the slag (molten metal) solidified in the plasma melting furnace 13. The slag (molten metal) melted in this way exhibits conductivity again. Therefore, a current path of the second power source 8 → the metal electrode type plasma torch 3 → the molten slag (molten metal) → the furnace bottom electrode 6 → the second power source 8 is established, and in this state, the switch 11 is opened to open the graphite electrode type plasma. Even if the torch 2 is disconnected from the furnace bottom electrode 6, the metal electrode type plasma torch 3 can continue to generate arc plasma in a stable state (see FIG. 3). If the switch 12 is closed in this state, as described above, electric power can be supplied from the first power source 7 to the graphite electrode type plasma torch 2 to generate arc plasma (see FIG. 4).

  According to the waste processing plasma melting apparatus 1 of the present embodiment configured as described above, arc plasma instability in the vicinity of the waste inlet 4 is avoided, and at the same time, slag (molten metal) is in the vicinity of the outlet 5. ) Can be accurately heated to prevent clogging at the time of tapping, so that the plasma melting furnace 13 can be operated in a stable state. In addition, by controlling the power supplied to these plasma torches 2 and 3 as well as cooling water and gas independently, precise control according to the situation such as the input of waste, the discharge of molten metal 14 and the progress of melting is possible. Can be operated with high energy efficiency.

  Moreover, when the plasma melting treatment apparatus 1 for waste treatment is started, arc plasma is once generated between the two plasma torches 2 and 3 arranged at the front and rear to melt the solidified slag and restore conductivity. Thus, a starting method has been established on the premise that there is no conductivity of the solidified slag, such as heating control of each plasma torch 2 and 3 independently. For this reason, it is possible to start easily at the time of starting. In particular, when the device 1 itself is further reduced in size, coupled with the electric heating system, it becomes easier to start and stop than other devices.

  Further, the plasma melting processing apparatus 1 for waste processing according to the present embodiment that performs plasma melting has the following merits. That is, since an extremely high temperature can be generated relatively easily, there are advantages such as achievement of a high processing speed, compactness of the apparatus, and a wide acceptance margin for various types of waste (various miscellaneous materials can be melted). Further, since there are few exhaust gases as a feature of electric heating, there are advantages that the exhaust gas treatment facility can be made compact, the powder can be handled easily (it is difficult to be discharged on the exhaust gas), and it is suitable for fly ash treatment. Furthermore, as another feature of electric heating, energy management and control are easy, and there is also an advantage that optimization of operating conditions is easy. In addition, another feature of electric heating is that it has relatively little influence on the heating energy from chemical reactions that proceed in the heating field, so that stable heating can be maintained even if the composition of the waste fluctuates. There is a merit that it is easy.

  Subsequently, a configuration for making the plasma melting treatment apparatus 1 for waste treatment described so far portable will be described below. The waste processing plasma melting processing apparatus 1 according to the present embodiment selects an ultra-high temperature plasma as a heating source and obtains a heating source with a high temperature and a high energy density, thereby enabling an improvement in processing speed. In addition, the plasma melting furnace 13 can be made compact. In addition, since the amount of exhaust gas is small due to electric heating, the exhaust gas treatment facility can be made compact. Furthermore, since the wet method is adopted for the exhaust gas treatment, wastewater treatment is necessary, but even if this is included, it is possible to achieve a more compact size than the dry method. In addition, when the size of the plasma melting furnace 13 is reduced, the overall heat capacity is reduced. Therefore, in combination with the arrangement of the metal electrode type plasma torch 3 having high directivity on the waste outlet 5 side, By raising the temperature of the molten metal 14, troubles such as clogging of the hot water outlet 5 can be avoided and smoother hot water can be performed. In the present embodiment, the above-described waste processing plasma melting treatment apparatus 1 is configured to be able to be loaded on a moving medium 21 such as a vehicle, a ship, a freight car, an airplane, and the like. (See FIG. 7 etc.)

  First, the portable waste processing plasma melting apparatus 1 and the pretreatment apparatus 22 according to the present invention are shown (see FIGS. 7 and 8). Here, a state in which the above-described waste processing plasma melting treatment apparatus 1 is loaded on a track which is an example of the moving medium 21 is shown. In addition, a pretreatment device 22 is loaded at the rear of the waste treatment plasma melting treatment device 1. The pretreatment device 22 includes a conveyor 23, a bag breaker 24, a transport conveyor 25, a dryer 26, a transport conveyor 27, and a damper 28 (see FIG. 7 and the like).

  A conveyor 23 for supplying waste to the crusher 24 is provided at the rear of the pretreatment device 22 (see FIGS. 7 and 8). The conveyor 23 is preferably foldable so that it can be accommodated in the loading portion (loading platform) of the moving medium 21 except when the waste is supplied. In addition, since waste is harmful, it is generally transported in a bag-like state such as packed in a flexible container pack (polymer bag).

  The bag breaker 24 is a device that facilitates the subsequent drying / melting process. If the waste supplied by the conveyor 23 is packed in, for example, a flexible container pack, the flexible container pack is removed. A process of breaking and taking out from the bag is performed. In this case, the size of the waste packed in the bag varies depending on the type of the waste and the processing scale of the processing apparatus 1 that handles the waste. As an example, the bag breaker in the present embodiment is used. No. 24 accepts waste that is about the size of a brick (for example, 230 × 115 × 65 mm or less), and also accepts that the waste is delivered in a flexible container pack.

  The conveyance conveyor 25 is a conveyor for conveying the waste taken out by the bag breaking machine 24 and the flexible container pack torn away by the bag breaking machine 24 to the dryer 26 where the next stage processing is performed.

  The dryer 26 is a device that performs a process of evaporating water contained in the waste, and the process by the dryer 26 is necessary to reduce the burden on the exhaust gas treatment system. That is, when moisture contained in the waste enters the plasma melting furnace 13, the volume increases, and the amount of exhaust gas to be treated becomes extremely large, resulting in a large exhaust gas treatment facility, and exhaust gas. When dew condensation occurs in the treatment system, there is a concern that acid gas and water will react to produce acid, which will cause damage to the exhaust gas treatment system. However, waste is thrown into the plasma melting furnace 13. If dehydration is performed before, the amount of water flowing into the exhaust gas treatment system can be reduced, and the exhaust gas treatment facility can be made compact. In addition, when performing a drying process with this dryer 26, it is preferable to perform an evaporation process until the moisture content in waste becomes 1/10 or less. For example, if the moisture contained in the waste is 30 wt%, it will be evaporated to about 3 wt%, which is 1/10 or less.

  The transport conveyor 27 is a conveyor for transporting the waste that has been dried by the dryer 26 to the plasma melting furnace 13. The waste transported by the transport conveyor 27 is input to the waste input cylinder 4a connected to the waste input port 4 (see FIG. 7).

  The damper 28 is provided as a device that prevents the high-temperature gas from the waste processing plasma melting processing apparatus 1 from flowing back to the pretreatment apparatus 22. In other words, when the waste is transferred to the waste processing plasma melting treatment apparatus 1, there is a portion equal to the atmospheric pressure. However, if the damper 28 is provided with a partition to maintain airtightness, a negative pressure can be maintained. Becomes easy. From the viewpoint of easily maintaining the airtightness of the plasma melting furnace 13, it is preferable to use a double damper as in the present embodiment (see FIG. 7). Further, the damper 28 of the present embodiment is an electric type with a flap.

  The basic configuration of the portable waste processing plasma melting apparatus 1 shown in FIGS. 7 and 8 is as described above (see FIGS. 1 to 6). From the viewpoint of performing the melting process efficiently and in a short time at the destination, in this embodiment, at least a portion (furnace body portion) including the plasma melting furnace 13 is tilted toward the tap 5. (See FIG. 7 etc.). Normally, the molten metal 14 in the plasma melting furnace 13 is discharged by overflowing the outlet 5 (see FIG. 1 and the like). In addition to this, the molten metal 14 is forcibly discharged by tilting the furnace body. I can do it. In short, the portable waste processing plasma melting treatment apparatus 1 according to the present embodiment can discharge hot water by either overflow or tilting. As described above, the specific configuration for enabling tilting of the waste melting plasma melting apparatus 1 itself or the furnace body portion including the plasma melting furnace 13 is not particularly limited. Is provided with a support base 29, and a support member 35 on the support base 29 supports the furnace body portion so as to be tiltable about a fulcrum 30, and a pair of left and right tilting hydraulic cylinders 31 are used to attach the furnace body portion to a tap. 5 (see FIGS. 9, 11, and 12). In this case, the maximum tilt angle can take various values depending on each configuration, but in the present embodiment, a tilt angle of about 60 degrees is secured, and most of the molten metal 14 in the plasma melting furnace 13 is used as the outlet 5. (See FIGS. 7 and 9).

  Furthermore, it is also preferable that the lid of the plasma melting furnace 13 (hereinafter referred to as “furnace lid”, denoted by reference numeral 32) of the plasma melting processing apparatus 1 for portable waste processing can be opened and closed. In such a case, maintenance of the plasma torches 2 and 3 and the plasma melting furnace 13 becomes easy. In the present embodiment, the support member 36 supports the furnace lid 32 so as to be tiltable in the front-rear direction around the fulcrum 33, and a pair of left and right hydraulic cylinders for opening and closing the furnace lid between the main body of the processing apparatus 1 and the furnace lid 32. As a structure in which 34 is installed, the furnace lid 32 opens and closes as the furnace lid opening / closing hydraulic cylinder 34 strokes (see FIGS. 10 to 12).

  Although not particularly shown in the present embodiment, the portable waste processing plasma melting processing apparatus 1 is provided with a coagulating apparatus as necessary. In addition, although the incinerator for combustible materials is not shown in the present embodiment, it is not necessary to include a new technology in particular, and a conventional product such as a commercial product can be used. Further, although not shown in the drawings, the portable waste processing plasma melting processing apparatus 1 of the present embodiment is provided with an exhaust gas processing facility. The exhaust gas discharged from the plasma melting furnace 13 contains dust, acid gases (HCl, NOx, SOx), etc., and the exhaust gas treatment equipment works after removing these until it meets the discharge environmental standards. To do.

  By the way, the portable waste processing plasma melting processing apparatus 1 described so far can be loaded on a moving medium 21, and depending on the specific size and loading capacity of various media such as vehicles, ships, freight cars, and airplanes. The size and weight can be changed as appropriate. However, from the viewpoint of improving versatility and portability, the overall size of the portable waste processing plasma melting treatment apparatus 1 is preferably smaller than the size of the container. In such a case, it is possible to mount the container on a freight car, a ship, or the like on which containers can be loaded with a margin, and the versatility and portability are improved by increasing the types and number of movable media 21 that can be loaded. . As a specific example of the container, for example, there is a 40-foot container (length 12 m, width 2.35 m, height 2.35 m) which is a size used in a ship and can be moved by a trailer. The size of the portable waste processing plasma melting processing apparatus 1 has been described so far, but the same applies to the preprocessing apparatus 22. That is, the pre-processing device 22 can also be changed as appropriate according to the specific size and loading capacity of the various moving media 21, and is preferably smaller than the size of the container. Needless to say, the portable waste treatment plasma melting treatment apparatus 1 and the pretreatment apparatus 22 have the required waste treatment capacity regardless of the size.

  Moreover, it is also preferable that the above-described portable waste processing plasma melting processing apparatus 1 and pretreatment apparatus 22 have a structure that can be folded as necessary. In such a case, it is possible to make it compact by folding it when loaded on the moving medium 21. For example, in the present embodiment, the supply conveyor 23 of the pretreatment device 22 is foldable so that it can be folded compactly during movement, and can be extended to the ground during waste disposal to convey waste to the bag breaker 24. (See FIG. 7).

  The moving medium 21 is a medium for loading and moving the portable waste processing plasma melting processing apparatus 1 described in this embodiment, and corresponds to a vehicle, a ship, a freight car, an airplane, and the like as described above. In this embodiment, a 25t track is illustrated and described as an example (see FIGS. 7 and 8). As shown in the figure, this truck is provided with outriggers 37 on both sides (grounding legs projecting outside of a machine or the like and projecting on the ground to maintain stability during operation).

  According to the portable waste processing plasma melting processing apparatus 1 of the present embodiment described so far, unlike the conventional waste processing apparatus, the waste processing plasma melting processing apparatus 1 is disposed at various places where harmful substances are generated. It goes to itself, and it becomes possible to carry out processing such as detoxification and recycling (slag formation) at that location. That is, in the past, it was inevitable to move various harmful substances to the processing base. However, according to the present invention, the risk associated with the movement of waste (waste transportation) because the apparatus itself has mobility. Can be completely avoided. Furthermore, if you move to various locations and perform waste treatment, it will be operated as a plasma melting treatment device by that amount, so it is inevitably expected that the operating rate will be greatly improved, and thus it is economically superior. It will be. In addition, since the processing equipment itself is located locally, it is advantageous in that it is not necessary to provide a final disposal facility far away even if harmful substances are scattered in various regions.

  In addition, it is advantageous in that it can be applied in various locations and in a wide area because it uses electric power with the most infrastructure as an energy source. Moreover, the use of clean energy such as electric power in this way also minimizes secondary environmental pollution.

  In addition, there are various operation methods when the portable waste processing plasma melting treatment apparatus 1 is put into operation, but as an example, it is assumed that a skilled operator is associated with the apparatus and the operation is performed exclusively. For example, it is possible to improve the stability of recycling quality and the safety of processing operations. From this point of view, it is also possible to improve mobility by packaging (unitization, unitization) as a waste treatment system, thereby improving stability and safety. It is done. As a specific example of packaging here, for example, a plasma melting furnace 13, a pretreatment device 22, and an exhaust gas treatment facility are separately assembled on a metal mold, and a moving medium such as a trailer is used at a place to be treated. A form in which the work is taken down from 21 can be considered, and if assembled separately in this way, it can be transported by a smaller moving medium 21 and can be moved easily. Further, if the heavy part of the plasma melting furnace 13 and the part of the pretreatment device 22 can be separated, the hanging weight of the crane necessary for the unloading work can be reduced. For example, the suspended weight of the crane is 50 tons after 10 tons, and it may be preferable to use a 10 ton crane with a smaller turn from the viewpoint of improving the workability of loading and unloading on site. In addition, if the piping to the exhaust gas treatment facility (not shown) is performed using a flexible duct, the connection work is facilitated. Also, the exhaust gas treatment facility may be assembled and transported in a separated state.

The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, in the present embodiment, a case has been described in which arc plasma is generated between the graphite electrode type plasma torch 2 and the metal electrode type plasma torch 3 as one method for realizing simple start-up. Can also be adopted. Hereinafter, another embodiment of the present invention in which another activation method is adopted is shown (see FIG. 13). The waste processing plasma melting apparatus 1 shown in FIG. 13 has the same configuration as the above-described waste processing plasma melting apparatus except that the conductive refractory 10 is provided. The conductive refractory 10 is partly connected to the furnace bottom electrode 6 as shown in the figure so as to have the same potential as that of the furnace bottom electrode 6, and in the case of this embodiment, the molten metal It is installed so as to extend to the waste inlet 4 side along the inner wall of the plasma melting furnace 13 so that it is higher than the liquid level of 14 and at least at a height at which slag does not adhere. The distance between the conductive refractory 10 and the tip of the graphite electrode type plasma torch 2 is approximately the same as the distance between the furnace bottom electrode 6 and the tip of the metal electrode type plasma torch 3. Suitable materials for the conductive refractory 10 include, for example, refractories containing graphite and carbon (MgO-C, dolomite-C, Al ₂ O ₃ -SiC-C, Al ₂ O ₃ -MgO-C ). When starting up the plasma melting treatment apparatus 1 for waste treatment, arc plasma can be generated between the conductive refractory 10 and the graphite electrode type plasma torch 2, and thereby the plasma melting treatment for waste treatment. The apparatus 1 can be easily activated. Here, an example has been described in which arc plasma is generated between the conductive refractory 10 and the graphite electrode type plasma torch 2, but conversely, the conductive refractory 10 and the metal electrode type plasma torch. Even if arc plasma is generated between the two, it can be started up easily.

  Although not particularly shown, the two plasma torches 2 and 3 may be arranged at two places in the front and rear as in the above-described embodiment, and further three or more plasma torches may be arranged in total. When three or more plasma torches are used in this way, either the graphite electrode type or the water-cooled metal electrode type is used for the plasma torch other than the plasma torch arranged near the waste inlet 4 and the outlet 5. Is used.

  Further, as an example of a structure in which the portion including the plasma melting furnace 13 (furnace body portion) can be tilted, in this embodiment, the furnace body portion is tilted toward the tap 5 (that is, tilted forward of the track). However, this is only an example. For example, depending on the arrangement of the above-described solidification device (not shown), it is possible to tilt the furnace body portion in the direction inclined 90 degrees as described above, that is, in the left or right direction of the track. Needless to say, in this case, the molten metal outlet 5 is provided on the side in the tilting direction or in the vicinity thereof.

  Further, although not particularly mentioned in the above-described embodiment, it can be said that it is also preferable to treat specially managed waste that is strictly classified as a treatment target. In such a case, if the combustible material and the non-combustible material are separated, it is possible to realize further compactization of the portable waste processing plasma melting treatment apparatus 1, and the separation treatment is performed in this way. In doing so, both combustible waste and non-combustible waste can be melted and detoxified.

  Furthermore, in the present embodiment, the explanation has been made on the assumption that one portable waste processing plasma melting treatment apparatus 1 is moved by one moving medium (truck) 21, but there are a plurality of objects in a certain target area. Of course, it is also possible to put in the portable portable plasma processing apparatus 1 for waste disposal. For example, in this case, since the processing capability in the same time zone is improved by that amount, the application target area can be easily expanded.

It is a conceptual diagram which shows one Embodiment of the plasma melting processing apparatus for waste processing which concerns on this invention. It is a figure which shows the electric current path | route at the time of starting of the plasma fusion processing apparatus for waste processing. It is a figure which shows the electric current path | route after cut | disconnecting a graphite electrode type plasma torch from a furnace bottom electrode. FIG. 4 is a view showing a state in which power is further supplied from a first power source to a graphite electrode type plasma torch in the waste processing plasma melting treatment apparatus shown in FIG. 3. It is the schematic which shows an example of the drive mechanism which rotates a plasma torch. It is the schematic which shows an example of the gas supply system to a graphite electrode type plasma torch and a metal electrode type plasma torch. It is a side view which shows the plasma melting processing apparatus for a portable waste disposal loaded on the track | truck which is an example of a moving medium, and this track | truck. FIG. 8 is a plan view of the portable waste processing plasma melting apparatus and the truck shown in FIG. 7. It is a side view of the plasma melting processing apparatus for portable waste processing which enabled tilting of the furnace part. It is a figure which expands and shows the furnace cover part made openable / closable among the plasma melting processing apparatuses for portable waste processing. It is a figure which shows the plasma melting processing apparatus for portable waste processing seen from the hot metal outlet side. It is a top view of the plasma melting processing apparatus for portable waste processing shown in FIG. It is a conceptual diagram which shows other embodiment of this invention, and represents the plasma melting processing apparatus for waste processing provided with the electroconductive refractory in the plasma melting furnace.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plasma melting processing apparatus 2 for waste treatment Graphite electrode type plasma torch 3 Metal electrode type plasma torch 4 Waste input port 5 Hot water outlet 6 Furnace bottom electrode 7 First power source 8 Second power source 9 Short circuit 10 Conductive fire resistance Object 11 Switch (of short circuit 9) 13 Plasma melting furnace 14 Molten metal 21 Moving medium

Claims (5)

A metal electrode that generates a highly directional arc plasma while a graphite electrode type plasma torch capable of continuing the melting process even when in contact with the waste to be melted is disposed near the waste inlet. The plasma melting torch is a wastewater treatment plasma melting treatment apparatus provided with a furnace bottom electrode facing the graphite electrode plasma torch and the metal electrode plasma torch. A first power source for supplying electric power to the graphite electrode type plasma torch and a second power source for supplying electric power to the metal electrode type plasma torch, wherein the graphite electrode type plasma torch and the metal electrode type plasma torch are respectively provided. In addition to controlling the heating independently, a short circuit that connects the graphite electrode type plasma torch and the furnace bottom electrode, and an open circuit that opens and closes the short circuit. A graphite electrode type plasma torch connected to the furnace bottom electrode to generate arc plasma between the graphite electrode type plasma torch and the metal electrode type plasma torch at the time of starting the plasma melting processing apparatus. The plasma melting process for portable waste treatment is characterized in that after the start-up is completed, the graphite electrode type plasma torch is separated from the furnace bottom electrode and can be loaded on a moving medium such as a vehicle, a ship, a freight car, an airplane, etc. apparatus. 2. The plasma melting apparatus for portable waste treatment according to claim 1, wherein at least one of the graphite electrode type plasma torch and the metal electrode type plasma torch can be moved toward and away from the other plasma torch . Provided with a conductive refractory having the same potential as the furnace bottom electrode installed at a height higher than the liquid level of the molten metal of the waste and at least not adhering to the slag. portable waste disposal for plasma melting treatment apparatus according to claim 1, wherein the generating the arc plasma between any one of the plasma torch of the present and the conductive refractories. At least plasma melting furnace inclusive furnace body portions are portable waste disposal for plasma melting treatment apparatus according to any one of claims 1 to 3, characterized that you have been a tiltable structure. The plasma melting apparatus for portable waste disposal according to any one of claims 1 to 4, wherein the apparatus is smaller than the size of the container .

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